Fin type field effect transistors (finFETs) are popular because of the increased miniaturization that they enable over other semiconductor devices. During the fabrication of finFETs semiconductor material that forms the fins may be subjected to the introduction of dopants, for example, boron and phosphorus. Conventional doping may result in interaction between the dopants, causing weak points and unwanted doping. Another method of introducing the dopants into the fins is through BSG and PSG layers. The BSG layer is formed on the p-type finFETs (p-FETS), a PSG is formed over both the p-FETs and the n-type finFETs (n-FETs), and then the PSG layer is removed, e.g. by etching, from the p-FETs. However, the etching tends to damage the BSG layer. Further, when the dopants are driven into the fins, some dopants go into the shallow trench isolation (STI) regions between the fins.
A need therefore exists for methodology enabling introduction of boron and phosphorus into semiconductor fins in a self-aligned manner with no dopants in the STI regions and the resulting device.